Pete Wentz and girlfriend Meagan Camper attended a charity event last night at Pinz Bowling Alley in Studio City, and as usual, the rocker was in good spirits as he posed for photographs and signed autographs for fans.

The Fall Out Boy musician has been going strong with his model girlfriend for some time now, but it's another woman who is reportedly causing stress in his life!

The bassist is rumored to be concerned about ex-wife Ashlee Simpson's drinking and her ability to care for their 4-year-old son Bronx.

"Pete is worried that Bronx's well-being could be affected if Ashlee continues to party hard, and he's concerned about her right now. With the situation as it is, if Ashlee doesn't sort herself out soon, Pete believes he will have no option but to go to the courts to get this matter resolved," a source dished to Radar.